包含广泛的

The title and bill of material in engineering drawings are important data source for product data integrated management. In order to reuse the CAD data, the paper presents an effective method for extracting part information from existing engineering drawings. Through analyzing the format of title and bill of material, several shape-position characteristics of tables are summed up from the view of macro-layout and microstructure. A new method to automatically extracting drawing information based on cell-grid and feature-point is proposed along with its algorithm principle and implementation steps. A software package based on the method mentioned above is developed and used in practice.

1引言工程图是工程设计的主要成果和制造加工的主要依据，CAD软件的广泛应用使得传统上对于纸质图纸的管理模式转变为对大量电子文件的管理模式·由于文件系统在实际应用中不能适应复杂大规模的管理模式，已经出现了各种各样的图档管理系统[1]·工程图中包含的零件信息在表现形式上体现纸格式的标准化为批量提取数据提供了可能性·作为计算机处理的对象，图纸信息自动识别成为数据管理和系统集成的一项关键技术·当前CAD管理系统所处理的数据对象比较复杂，面临由不同企业使用不同的绘图软件生成的图纸，其中的标题栏和明细栏或者由软件自动生

Based on the idea of type systems, this paper reengineers a new set of type expressions and a type system for machine code of Intel/x86s infrastructure Although machine language program is a binary untyped code, types of its registers and memory exist implicitly in semantics of instructions The type inferring algorithm built on type systems can statically infer safety of the machine code The machine language discussed includes some of important characters, such as jumps, function call, return, and so on, and shows that the approach can be applied to type checking for low level code of other infrastructures

根据类型系统思想，为Intel/x86体系结构的机器语言重新定义了类型表达式并建立一套类型系统机器语言代码虽然是一种无类型的二进制编码，但其类型信息被隐含在指令的操作语义中，利用建立在类型系统基础之上的类型推理算法可以静态地推理机器代码的安全性由于所讨论的机器语言包含了跳转、函数调用和返回等主要指令，因此，这种静态检查方法可广泛应用于其他体系结构的低级语言代码的检查中

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。